Background: In people with intellectual disabilities and mental disorders and/or challenging behaviours, rates of psychotropic drug prescription are high. In clinical treatments and evaluations, all stakeholders should be involved in a process of shared decision-making (SDM). We aimed to investigate the perspectives of clients and their carers on clients' treatments with psychotropic drugs. Methods: We conducted a survey among adults with intellectual disabilities in a Dutch mental healthcare centre providing community, outpatient and inpatient care. Data were collected between January and June 2022. Questions focused on experiences with the provision of information, treatment involvement and SDM and participants' wishes in this regard. Findings: Respondents (57 clients and 21 carers) were largely satisfied with the overall care from their clinicians, and with how information on the pharmacological treatment was provided verbally, but written information was insufficient or not provided. Seventy per cent of clients and 60% of carers reported being involved in medication decision-making. However, over 75% of participants desired greater involvement in SDM and over 60% in medication reviews. Conclusions: Service users and representatives were satisfied about the treatment and verbal information on their psychotropic drug use. The provision of written information, the SDM process and ongoing evaluation of psychotropic medication use could be improved.